2010 chevy camaro idle/low RPM tuning

[hapisok]

looking for some help/direction on nailing down my idle/low RPM tune.

current MODS:

Ed Curtis cam: 22*/23* 114 +3 .625/.600
CAI
Ported TB
LG motorsports LT
Exhaust & HF Cats
3.91 Gears

the rest of the tune seems to be dialed in…putting down decent power 458HP 425TQ

trying to get the idle portion dialed in as i have some surging and bucking at low speeds, mainly below 1400RPM. i've been through the forum and the "how to's" http://www.hptuners.com/forum/showth...e-(w-pictures) for instance, but the guides seem out dated for the version of software that i am running (2.24.57). i've been playing with the base idle airflow and increasing the values until the surging goes away, but I'm not certain that simply adding more air is the correct way of doing this. i have noticed my AFR (wideband) become more stable at lower RPM and holding between 14.5-14.9 steadily, but my LTFT/STFT's are between +10-15%, and in turn my MPG's have also suffered. instead of adding air, should i be pulling fuel, and if so, what would be the correct way, or should i look to add timing? i think my idle base spark vs rpm vs cylair could use some finesse just looking at it. i'd take the the correct way to go about doing it period if anybody has a recommendation.

any help would be appreciated.

thanks

[thahemp]

I just did some reading on this. My cam should be here next week. The approach I'm going to take is remove fuel, remove timing, and try not to mess with the idle airflow too much. Keep us posted though. I'm interested to see how you get it figured out. The HPT site is good, but there isn't a whole lot of info specific to our cars.

[hapisok]

being a noob at this i asked my tuner where to start and he said to start by adding air. it did help with the bucking issue and i was able to dial most of it out, but i know there is more to it than that. just not sure the best way to fine tune it with the other parameters. and you are absolutely right about there not being a lot of specific info. i found a video on the youtube that is the most up to date instructable: but which parameters and histograms to log and then manipulate leave me trying to muddle my way and make sense of the old "how to's". anyhow, i'll keep you posted fo sho.

thanks and Good luck with this one! yourself ; )

[JANNETTYRACING]

You have to dial in your MAF so your fuel trims end up +/- 2% before you mess with the Idle Air flow tables.

You can take the stock Idle air flow tables and add 3 Grams per to the whole table as a baseline starting point.

Not Lb per minute so make sure your tools are set to Metric.

Your on the right track.

Ted.

Originally Posted by hapisok

looking for some help/direction on nailing down my idle/low RPM tune.

current MODS:

Ed Curtis cam: 22*/23* 114 +3 .625/.600
CAI
Ported TB
LG motorsports LT
Exhaust & HF Cats
3.91 Gears

the rest of the tune seems to be dialed in…putting down decent power 458HP 425TQ

trying to get the idle portion dialed in as i have some surging and bucking at low speeds, mainly below 1400RPM. i've been through the forum and the "how to's" http://www.hptuners.com/forum/showth...e-(w-pictures) for instance, but the guides seem out dated for the version of software that i am running (2.24.57). i've been playing with the base idle airflow and increasing the values until the surging goes away, but I'm not certain that simply adding more air is the correct way of doing this. i have noticed my AFR (wideband) become more stable at lower RPM and holding between 14.5-14.9 steadily, but my LTFT/STFT's are between +10-15%, and in turn my MPG's have also suffered. instead of adding air, should i be pulling fuel, and if so, what would be the correct way, or should i look to add timing? i think my idle base spark vs rpm vs cylair could use some finesse just looking at it. i'd take the the correct way to go about doing it period if anybody has a recommendation.

any help would be appreciated.

thanks

[hapisok]

thanks ted…i appreciate the help.

[thahemp]

Originally Posted by JANNETTYRACING

You have to dial in your MAF so your fuel trims end up +/- 2% before you mess with the Idle Air flow tables.

You can take the stock Idle air flow tables and add 3 Grams per to the whole table as a baseline starting point.

Not Lb per minute so make sure your tools are set to Metric.

Your on the right track.

Ted.

Agreed. I see so many people saying to dial in the idle first. I can't get onboard with that logic. How in the hell are you supposed to dial in your idle if your car can't calculate airflow properly to start with? My guess is.. do it, then tune the rest, then DO IT AGAIN haha.

My cam specs are gonna be close to yours hapisok. About the same lift, but a little more exhaust duration and a little tighter LSA. I'm excited to get it in and get to work on the tune.

[Rhino79]

Cranking airflow and minimum airflow for start/idle. You really need to look into setting up the proportional and integral idle tables because the factory settings can really move the blade too aggressively at idle and decel.

Leave idle timing about stock, reduce the amount the over/undercorrection can add/subtract so the timing is pretty stable at idle.

Once you do all this, you should have a steady tps and idle timing setup.

Disable maf in tune. Disable LTFT. Work off the short terms. Tune the Ve or VVE to get the fueling right here first. VERY important. Because even when guys think they are setting up to run maf only, they aren't. The ve's are used for all transient fueling conditions, so you have to dial in ve's to get tip in and low speed fueling right.

Once you have the ve's dialed in, you KNOW that any fueling errors you have, are result of maf calibration. Dial it in, plus or minus 5% is really ok, your trims will vary from day to day a little bit.

Dynamic airflow or MAF ONLY so to speak. I set them lower than stock, usually around 2500 rpm enable, 2400 disable. The maf is great a more steady airflow measurement, but isn't so good at idle and low speeds because of reversion in the intake system.

Once fueling is dialed in at part throttle and WOT, tune the ignition advance. If you have spark knock, and fuel is good, reduce timing by 2/3 the amount you saw in that rpm range. You may also want to set up the knock recovery rate a little higher so you can more accurately pinpoint where true knock is occurring on the datalog, rather than have a chunk of timing pulled for an extended period of time.

Now if you want to turn LTFT back on, go for it, I choose not to on cammed cars, I don't want ANY fuel trims going into wot, whether its 1% or 5%. I want open loop to be open loop.

Obviously always make sure injector data and displacement data is correct.

[Rhino79]

Originally Posted by thahemp

Agreed. I see so many people saying to dial in the idle first. I can't get onboard with that logic. How in the hell are you supposed to dial in your idle if your car can't calculate airflow properly to start with? My guess is.. do it, then tune the rest, then DO IT AGAIN haha.

My cam specs are gonna be close to yours hapisok. About the same lift, but a little more exhaust duration and a little tighter LSA. I'm excited to get it in and get to work on the tune.

I agree, but you have to touchup aiflow most times just to get the car to run enough to dial fueling in.

[thahemp]

Originally Posted by Rhino79

Cranking airflow and minimum airflow for start/idle. You really need to look into setting up the proportional and integral idle tables because the factory settings can really move the blade too aggressively at idle and decel.

Leave idle timing about stock, reduce the amount the over/undercorrection can add/subtract so the timing is pretty stable at idle.

Once you do all this, you should have a steady tps and idle timing setup.

Disable maf in tune. Disable LTFT. Work off the short terms. Tune the Ve or VVE to get the fueling right here first. VERY important. Because even when guys think they are setting up to run maf only, they aren't. The ve's are used for all transient fueling conditions, so you have to dial in ve's to get tip in and low speed fueling right.

Once you have the ve's dialed in, you KNOW that any fueling errors you have, are result of maf calibration. Dial it in, plus or minus 5% is really ok, your trims will vary from day to day a little bit.

Dynamic airflow or MAF ONLY so to speak. I set them lower than stock, usually around 2500 rpm enable, 2400 disable. The maf is great a more steady airflow measurement, but isn't so good at idle and low speeds because of reversion in the intake system.

Once fueling is dialed in at part throttle and WOT, tune the ignition advance. If you have spark knock, and fuel is good, reduce timing by 2/3 the amount you saw in that rpm range. You may also want to set up the knock recovery rate a little higher so you can more accurately pinpoint where true knock is occurring on the datalog, rather than have a chunk of timing pulled for an extended period of time.

Now if you want to turn LTFT back on, go for it, I choose not to on cammed cars, I don't want ANY fuel trims going into wot, whether its 1% or 5%. I want open loop to be open loop.

Obviously always make sure injector data and displacement data is correct.

Originally Posted by Rhino79

I agree, but you have to touchup aiflow most times just to get the car to run enough to dial fueling in.

Thanks Ryan. There are several tidbits in there that I hadn't come across yet. I think the knock recovery rate might help me get some of my KR under control. I can never tell exactly what happened. Hurry up and try that stuff hapisok! Curious minds want to know .

[Rhino79]

For the trims below 2000 rpm, look and see what RPM your Hi speed enable/disable is set to. you may need to work the ve rather than the maf.

I like to drive about 10 mins-15 mins, then start a new log with STFT histogram or Map to see how they look for each Maf Freq row, After I have dialed Ve in first using the same method

[thahemp]

Originally Posted by Rhino79

For the trims below 2000 rpm, look and see what RPM your Hi speed enable/disable is set to. you may need to work the ve rather than the maf.

I like to drive about 10 mins-15 mins, then start a new log with STFT histogram or Map to see how they look for each Maf Freq row, After I have dialed Ve in first using the same method

Yes. I bet it's your VE. I had a weird stumble while VE tuning just after 2k rpm and light load. It took a couple tries manually massaging the data and interpolating before it went away. Just lacking data points I assumed. MAF only mode the problem wasn't there.

[thahemp]

And I just want to say... It's nice to see some real tuning discussion here. I hope this continues. Thanks ryan and ted.

[Slowhawk]

I can't read the log but at 1400 rpm light throttle I've seen dfco cut in and mess with timing at that area causing bucking. Changing the dfco fixes it.

[Rhino79]

Originally Posted by thahemp

Yes. I bet it's your VE. I had a weird stumble while VE tuning just after 2k rpm and light load. It took a couple tries manually massaging the data and interpolating before it went away. Just lacking data points I assumed. MAF only mode the problem wasn't there.

Its not that its lacking data points, but you also have to change Operating zone RPM and MAP boundary settings sometimes to get it right.

Man its much quicker in EFILive....lol.